diff --git a/vertx/etc/README.md b/vertx/etc/README.md
new file mode 100644
index 0000000000..4d71614ae4
--- /dev/null
+++ b/vertx/etc/README.md
@@ -0,0 +1,3 @@
+This directory contains files that are needed at runtime.
+
+jbossts-properties.xml is the configuration file for the version of JBossTS/Narayan we're using. You probably shouldn't try changing this without understanding the implications.